JP2018136438A - Lens barrel and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel and imaging device that can prevent an inadvertent movement of a focus position upon users's operations.SOLUTION: A lens barrel 1 comprises: an optical system that has a plurality of lenses L2 and L3; and focus adjustment mechanisms 4 and 5 that move the lens L2 of a part of the optical system in an optical axis direction to automatically or manually conduct focus adjustments. The focus adjustment mechanisms 4 and 5 comprise a differential mechanism 6 that has two input parts connected, in which to one input part, a manual focus adjustment mechanism 5 is connected that conducts the focus adjustment by a manual operation, and to other input part, an automatic focus adjustment mechanism 4 is connected that actuates an actuator to conduct the focus adjustment. The lens barrel has a release mechanism 8 that releases a connection of the manual focus adjustment mechanism 5 to the differential mechanism 6, and in a circumferential surface of the lens barrel 1, has a release operation member 85 for operating the release mechanism 8 disposed movably and operably in a circumferential direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a lens barrel and an imaging apparatus using the lens barrel.

As a lens barrel such as an interchangeable lens used for an autofocus single-lens reflex camera or the like, an automatic focus adjustment means (autofocus means) and a manual focus adjustment means (manual focus means) are provided, and any adjustment means without a switching means There is known a lens barrel that can be adjusted in focus. In such a lens barrel, when the manual focus adjustment means is connected to a drive ring that drives a lens group that performs focus adjustment in the lens barrel, the user can adjust the focus after the automatic focus adjustment means. When the manual focus adjustment unit is inadvertently operated, the drive ring is moved, and the lens is shifted from the adjusted focus position.

In order to deal with such a problem, Patent Document 1 discloses a lens barrel that can perform automatic focus adjustment and manual focus adjustment without switching using a differential mechanism for focus adjustment. A technique has been proposed in which means is provided for preventing transmission of force from the manual focus adjustment means to the differential mechanism during automatic focus adjustment by moving the selected switch knob in the optical axis direction.

  Similarly, in Patent Document 2, a focus operation ring for manual focus adjustment is provided on an optical axis in a lens barrel that can perform automatic focus adjustment and manual focus adjustment without switching using a differential mechanism for focus adjustment. A technique has been proposed in which the focus operation ring and the differential mechanism are connected to each other or can be released by being movable in the direction.

Japanese Patent Laid-Open No. 3-14412 JP 2000-249892 A

  In each of the techniques of Patent Documents 1 and 2, a member provided in the lens barrel is operated to move in the optical axis direction of the lens barrel, and the manual focus adjusting means is connected to the differential mechanism, or the connection is released. It has a configuration. Therefore, the user needs to move the member in the direction of the optical axis with one hand during shooting, and this operation makes the holding of the imaging device such as a camera held with the other hand unstable. easy. Further, the imaging device itself or the lens barrel itself is moved by the movement operation in the optical axis direction, and is finely moved in the optical axis direction, so that the focus position is likely to shift. In particular, the focus adjustment tends to become severe during close-up photography (macro photography) and the like, and this problem appears more prominently.

  Further, since the technique of Patent Document 1 is configured to prevent transmission of force from the manual focus adjustment means by the rotation prevention key integrated with the switching means entering the stopper groove, the stopper groove and the rotation prevention key If the phase does not match, the rotation of the focus operation ring cannot be restricted, and the problem of preventing the focus operation ring from shifting from the focus position when the phase is matched cannot be solved.

  On the other hand, since Patent Document 2 is configured to move a focus operation ring for manual focus adjustment, the focus operation ring is operated when the focus operation ring is operated in the optical axis direction to release the connection with the differential mechanism. It is difficult to prevent the operation ring from rotating, and the focal position is likely to shift.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lens barrel and an imaging apparatus that can prevent a focal position from being inadvertently moved during a user operation.

  The present invention includes an optical system having a plurality of lenses, and a focus adjustment mechanism that adjusts the focus by moving a part of the lenses of the optical system in the optical axis direction. The focus adjustment mechanism includes two input units. A manual focus adjustment unit that performs focus adjustment by manual operation is connected to one input unit, and an automatic focus adjustment unit that performs focus adjustment by an actuator is connected to the other input unit. The lens barrel has a release mechanism for releasing the connection of the manual focus adjusting means to the differential mechanism, and the lens barrel has a release operation member for operating the release mechanism in the circumferential direction of the lens barrel. It is arranged so that it can be moved.

According to the present invention, in a lens barrel including an automatic focus adjustment unit and a manual focus adjustment unit, the focus position does not shift even when the user operates the release operation member.

1 is a front view of an imaging device (camera) equipped with a lens barrel of the present invention. FIG. 3 is a left side view in which a part of the lens barrel of Embodiment 1 is broken. 1 is a longitudinal sectional view along the optical axis direction of the lens barrel of Embodiment 1. FIG. The longitudinal cross-sectional view at the time of the connection of the principal part containing a cancellation | release mechanism and a differential mechanism. The longitudinal cross-sectional view at the time of cancellation | release of the principal part containing a cancellation | release mechanism and a differential mechanism. The external appearance perspective view of an output ring. FIG. 4B is a cross-sectional view taken along line AA in FIG. 4A. The partial exploded perspective view of a cancellation | release mechanism. The schematic diagram for demonstrating operation | movement of a cancellation | release mechanism. FIG. 6 is a longitudinal sectional view when the lens barrel of Embodiment 2 is connected. FIG. 6 is a longitudinal sectional view when the lens barrel of Embodiment 2 is released. The partial exploded perspective view of a cancellation | release mechanism. FIG. 6 is a longitudinal sectional view when the lens barrel of Embodiment 3 is connected. FIG. 6 is a longitudinal sectional view when the lens barrel of Embodiment 3 is released.

(Embodiment 1)
FIG. 1 is a front view of a state in which the lens barrel 1 of the present invention is mounted on a camera body 2 as viewed from the front side (subject side), and FIG. 2 is a left side view in which a part of the lens barrel 1 is broken. . A focus operation ring 73 is disposed on the front side of the peripheral surface of the lens barrel 1, and the user rotates the focus operation ring 73 around the optical axis of the lens barrel 1 (hereinafter simply referred to as rotation). Manual focusing can be performed by operating. A zoom operation ring 63 is disposed on the rear surface side (image surface side) of the peripheral surface of the lens barrel 1, and the focal length of the lens barrel 1 is changed by rotating the zoom operation ring 63 by the user. Can be made.

  A part of the left peripheral surface of the lens barrel 1 has an intermediate position in the optical axis direction of the lens barrel 1 (hereinafter simply referred to as the optical axis direction), that is, the focus operation ring 73 and the zoom operation ring 63. The release switch 85 of the release mechanism 8 for releasing manual focus adjustment to an incapable state is disposed between the Although details of the release mechanism 8 will be described later, manual focus adjustment (manual focus) with the focus operation ring 73 is performed when the user slides the release switch 85 in the circumferential direction along the peripheral surface of the lens barrel 1. The state to enable is switched to the state to cancel and disable it. Here, when the slide operation is performed in the downward direction and the release state is established, the manual focus adjustment cannot be performed even if the focus operation ring 73 is operated.

  FIG. 3 is a longitudinal sectional view of the lens barrel, and only the members deeply related to the present invention are hatched. In the lens barrel 1, a first group lens L1, a second group lens L2, a third group lens L3, a fourth group lens L4, and a fifth group lens L5 are arranged from the left side in FIG. The first to fifth group lenses L1 to L5 move in the optical axis direction of the lens barrel 1 when the zoom operation ring 63 is rotated, and change the focal length of the lens barrel 1. The second group lens L2 is configured as a focus lens for performing focus adjustment by moving in the optical axis direction during zooming and focus adjustment.

  A focus motor 3 is disposed near the image plane in the lens barrel 1. The rotation of the focus motor 3 is controlled by, for example, an automatic focus control device (not shown) provided in the camera body 2. When the focus motor 3 is rotated, the second group lens L 2 is moved in the optical axis direction to perform automatic focus adjustment. It is something to execute. The focus motor 3 constitutes a part of an actuator for automatic focus adjustment in the present invention. Here, a DC motor is employed as the focus motor 3, but a brushless DC motor, a stepping motor, an ultrasonic motor, or the like may be used.

  Thus, as can be seen from FIG. 2, the lens barrel 1 of Embodiment 1 has the focus motor 3 at the image plane side position, the focus operation ring 73 at the subject side position, and the release switch 85. The focus motor 3 and the focus operation ring 73 are set at intermediate positions in the optical axis direction.

  In the lens barrel 1, an automatic focus adjustment mechanism 4 driven by the focus motor 3, a manual focus adjustment mechanism 5 driven by the focus operation ring 73, and the automatic focus adjustment mechanism 4 and manual focus adjustment. A differential mechanism 6 that links the mechanism 5 is provided. This differential mechanism 6 automatically adjusts the focus of the second lens group L2 by the automatic focus adjustment mechanism 4 when the focus motor 3 is rotated, and on the other hand, the manual focus adjustment mechanism 5 It becomes possible to manually focus the group lens L2. The manual focus adjustment mechanism 5 and the differential mechanism 6 are intermittently connected by the release switch 85 attached to the differential mechanism 6. When the linkage is released, the manual focus adjustment by the focus operation ring 73 becomes impossible as described above.

  The lens barrel 1 includes a first fixed ring 91 including a lens mount 90. A second fixed ring 92 and a third fixed ring 93 on the inner diameter side are connected to the first fixed ring 91. The focus operation ring 73 and the zoom operation ring 63 are supported by the second and third fixed rings 92 and 93. A rear support ring 53 is connected to the inner diameter position of the second fixed ring 92, and a front support ring 50 is connected to the subject side of the rear support ring 53. Further, a second support ring 57 is connected to a connecting portion between the front and rear support rings 50 and 53.

  A rectilinear ring 32 and a zoom cam ring 31 are arranged concentrically at the inner diameter position of the rear support ring 53 sequentially in the inner diameter direction. At the inner diameter position of the zoom cam ring 31, the third group lens frame 21 holding the third group lens L3, the focus cam ring 12, and the second group lens frame 11 holding the second group lens L2 are arranged concentrically. The first group lens frame 15 is disposed at the inner diameter position on the subject side of the zoom cam ring 31, and the fourth group lens frame 16 and the fifth group lens frame 17 are disposed at the inner diameter position on the image plane side.

  The zoom cam ring 31 is provided with a cam groove 31a penetrating the inner and outer diameters, and the rectilinear movement 32 is provided with a vertical groove 32a extending in the optical axis direction. Say) 21a is sliding. In addition, the roller 15a provided in the first group lens frame 15 is slid in the cam groove 31b and the vertical groove 32b provided in the zoom cam ring 31 and the rectilinear ring 32, and similarly in the cam groove 31c and the vertical groove 32c. The roller 16a provided on the fourth group lens frame 16 is sliding. Further, the roller 17 a provided in the fifth group lens frame 17 is in sliding contact with the longitudinal groove 16 b provided in the fourth group lens frame 16.

  Thereby, when the zoom operation ring 63 is manually operated and the zoom cam ring 31 is rotated, the first group lens frame 15 and the third group lens frame 21 move in the optical axis direction, and the first group lens L1 and the third group lens L3 are moved. Moving. The rotation of the zoom cam ring 31 moves the first group lens frame 15, the fourth group lens frame 16, and the fifth group lens frame 17 in the optical axis direction together with the third group lens L3. Further, the second group lens frame 11 is also interlocked. And move in the direction of the optical axis. Thereby, the first to fifth group lenses L1 to L5 are moved, and the focal length of the lens barrel 1 is changed.

  A circumferential groove 21b is provided on the inner peripheral surface of the third group lens frame 21, and a plurality of balls 14 arranged circumferentially in the circumferential groove 21b are sandwiched between the focus cam ring 12 and The focus cam ring 12 is rotatably held therein. The focus cam ring 12 has a cam groove 12a penetrating the inner and outer diameters. The third group lens frame 21 is provided with a longitudinal groove 21c extending in the optical axis direction. In addition, a roller 11a provided on the outer periphery of the second group lens frame 11 passes through the cam groove 12a and slides into the vertical groove 21c. As a result, the rotation of the second group lens frame 11 is restricted and can be moved only in the optical axis direction.

  A focus lever 13 extending to the image plane side in the optical axis direction is fixed to the focus cam ring 12 with a screw (reference numeral omitted). The focus lever 13 rotates in response to the output of the differential mechanism 6, and by this rotation, the focus cam ring 12 rotates integrally, and at the same time, advances and retreats in the optical axis direction together with the focus cam ring 12.

  FIG. 4A is a longitudinal sectional view of a region including the differential mechanism 6, showing only a part of FIG. 3 and attaching the reference numerals only to the main parts. The differential mechanism 6 is a region between the second fixed ring 92 and the rectilinear ring 32 in the radial direction, and in the optical axis direction between the focus operation ring 73 and the focus motor 3 shown in FIG. It is arranged in the area between. This differential mechanism 6 is constituted by a so-called planetary mechanism, and has a structure based on first and second solar wheels, a plurality of planets, and a planet carrier that supports these planets, as will be described later. is there.

  An output ring 51 is disposed on the outer diameter side of the rear support ring 53. A circumferential groove 53 a is provided on the outer peripheral surface of the rear support ring 53, and a plurality of balls 54 arranged in the circumferential direction in the groove 53 a are interposed between the output ring 51 and the output ring 51. 51 does not move in the optical axis direction with respect to the rear support ring 53, but is rotatably held around the optical axis.

  5 is an external perspective view of the output ring 51, and FIG. 6 is a cross-sectional view taken along the line AA in FIG. 4A. An output lever 52 extending in the direction of the optical axis is fixed to the output ring 51 with a screw, and the tip of the output lever 52 slides on the focus lever 13. This sliding is integral in the rotation direction and free in the optical axis direction. Therefore, when the output ring 51 rotates, the output lever 52 rotates, and further, the rotation is transmitted to the focus lever 13, and the focus cam ring 12 integrated therewith rotates. As described above, the rotation of the focus cam ring 12 causes the second group lens frame 11 to advance and retract in the optical axis direction to perform focus adjustment.

  In addition, three rotation shafts 51a extending in the outer diameter direction are provided at three locations in the circumferential direction on the outer peripheral surface of the output ring 51, and a circular planetary roller 55 is formed on the rotation shaft 51a. I'm in play. Further, the lid 56 is screwed to the output ring 51 from the outer diameter side to prevent the planetary roller 55 from coming off. The planetary roller 55 and the output ring 51 constitute a planet and a planet carrier of the planetary mechanism, respectively.

  As shown in FIG. 4A, a drive gear ring 61 and a drive ring 71 are arranged in the lens barrel 1 so as to sandwich these three planetary rollers 55 in the optical axis direction. A second wave washer 62 is interposed between the drive gear ring 61 and the third fixed ring 93 on the image plane side. The second wave washer 62 urges the drive gear ring 61 toward the subject side, and the urging force causes the sliding surface 61 a on the subject side of the drive gear ring 61 to have a peripheral surface on the image plane side of the planetary roller 55. Is in pressure contact.

  Further, an internal gear 61b is provided on the image plane side edge of the drive gear ring 61, and the focus motor 3 is connected to the internal gear 61b via a gear mechanism (not shown). As a result, the drive gear ring 61 rotates in conjunction with the rotation of the focus motor 3. The drive gear ring 61 rotates the planetary roller 55 pressed by this rotation to rotate the output ring 51, and further rotates the focus cam ring 12 to perform focus adjustment by the second group lens L2. A part of the focus adjustment mechanism 4 is constituted. The drive gear ring 61 constitutes one input portion of the differential mechanism 6 and constitutes the second solar wheel of the planetary mechanism described above.

  The drive ring 71 that sandwiches the planetary roller 55 from the subject side has an end surface on the image plane side as a sliding surface 71a, and the sliding surface 71a faces the planetary roller 55 in the optical axis direction. A first wave washer 72 is interposed between a step surface (not shown) provided in an intermediate part of the drive ring 71 and the front support ring 50 in the optical axis direction. The first wave washer 72 urges the drive ring 71 to the image plane side in the optical axis direction, and the slidable surface 71 a is pressed against the object-side peripheral surface of the planetary roller 55 by this urging force. .

  On the outer periphery of the drive ring 71 on the subject side, rollers 71b are planted in the outer diameter direction at a plurality of locations in the circumferential direction, and these rollers 71b are provided on the inner peripheral surface of the focus operation ring 73. They are respectively slid into the plurality of longitudinal grooves 73a in the optical axis direction. As a result, the drive ring 71 can move relative to the focus operation ring 73 in the optical axis direction. However, when the user rotates the focus operation ring 73, the drive ring 71 is brought into sliding contact with the vertical groove 73a and the roller 71b. Is rotated. When the sliding surface 71a is in pressure contact with the planetary roller 55, the planetary roller 55 is rotated by the rotation of the drive ring 71, the output ring 51 is rotated, and further, the focus cam ring 12 is rotated, thereby the second group lens. Since the focus adjustment by L2 is performed, a part of the manual focus adjustment mechanism 5 is configured. The drive ring 71 constitutes another input part of the differential mechanism 6 and constitutes the first solar wheel of the planetary mechanism described above.

  The operation of the differential mechanism 6 will be described. 4A, when the focus motor 3 is driven during automatic focus adjustment, the drive gear ring 61 is rotated, and the driving force is transmitted to the planetary roller 55 that is in pressure contact with the sliding surface 61a. The planetary roller 55 rotates around the rotation axis 51 a of the output ring 51. At this time, the drive ring 71 on the object side is stationary without rotating due to the friction torque generated between the first wave washer 72. Therefore, the output ring 51 rotates around the optical axis while the planetary roller 55 rotates around the rotation axis 51a. At this time, the output ring 51 rotates with a rotation amount substantially half that of the drive gear ring 61.

  On the other hand, when the user operates the focus operation ring 73, the drive ring 71 is rotated, and the driving force is transmitted to the planetary roller 55 pressed against the sliding surface 71a, so that the planetary roller 55 is rotated by the rotation shaft 51a of the output ring 51. Rotate around. At this time, the drive gear ring 61 on the image plane side is stationary without rotating due to the frictional torque generated between the second wave washer 62. Therefore, the planetary roller 55 rotates around the rotation axis 51a, and the output ring 51 rotates around the optical axis.

Here, in the differential mechanism 6, the rotational torque of the output ring 51 necessary for moving the second group lens L2 in the optical axis direction is T1, the driving torque of the driving ring 71 rotated during manual focus adjustment is T2, and automatic The drive torque of the drive gear ring 61 rotated during focus adjustment is T3, the friction torque generated between the drive ring 71 and the first wave washer 72 is T2 ′, and between the drive gear ring 61 and the second wave washer 62. When the friction torque generated in step S3 ′ is T3 ′ and the reduction ratio of the differential mechanism 6 is r, the following relationship must be satisfied.
rT1 <T2
rT1 <T3
T3 <T2 '
T2 <T3 '

  On the other hand, the operation torque when the user operates the focus operation ring 73 depends on the static friction torque and the dynamic friction torque generated between the drive ring 71 and the first wave washer 72. It is desirable that the operating torque is not too heavy, not too light, and becomes an appropriate torque. In the differential mechanism of Patent Document 2, there is only one pressing member that applies friction torque, corresponding to the second wave washer of this embodiment. In particular, when a vibration wave motor is used as the actuator of the automatic focus adjustment means, the pressing member for biasing the rotor also serves as the pressing member for pressing against the planetary roller of the differential mechanism. The biasing force of the member was determined by the biasing force necessary for the vibration wave motor to operate stably. Therefore, there is no degree of freedom in determining the urging force of the pressing member, and it has been difficult to adjust the operating torque of the operating ring to an appropriate torque.

  In the first embodiment, since the driving ring 71 and the driving gear ring 61 are urged by the first wave washer 72 and the second wave washer 62, respectively, the urging force can be adjusted independently. If it is within the range satisfying the conditions of T1, T2, T3, T2 ′, and T3 ′, for example, by setting the biasing force of the first wave washer 72 to be weak, the operation torque of the focus operation ring 73 is lightened. Can be set.

  When the output ring 51 rotates as described above, the output lever 52 integral with the output ring 51 rotates as described above, and further, the rotation is transmitted to the focus lever 13, and the focus cam ring 12 integral therewith rotates. To do. The rotation of the focus cam ring 12 causes the second group lens frame 11 to move back and forth in the optical axis direction to perform focus adjustment. That is, in the state shown in FIG. 4A, both automatic focus adjustment and manual focus adjustment are possible. Therefore, when the user operates the focus operation ring 73 when the focus is adjusted by the automatic focus adjustment, the output ring 51 rotates through the differential mechanism 6 and the focus position is shifted.

  A release mechanism 8 for solving such a problem will be described. FIG. 7 is a partially exploded perspective view of the release mechanism 8. An annular release member 81 is disposed at the outer diameter position of the drive ring 71, and release release switching is performed on the image plane side so as to be sandwiched in the optical axis direction. A ring 82 is provided, and a presser ring 84 is disposed on the subject side. The release switching ring 82 is disposed at an optical axis position surrounding the output ring 51.

  The release switching ring 82 is rotatably held at the inner diameter position of the second fixed ring 92. A plurality of (six in this case) release cams 82a are formed in the circumferential direction on the surface where the release switching ring 82 faces the release member 81, that is, the surface on the subject side in the axial direction. Further, the release switch ring 82 is provided with an engagement key 82b extending backward, and is engaged with an engagement groove 86a of a release switch mounting member 86, which will be described later, supporting the release switch 85. Accordingly, the release switching ring 82 is connected to the release switch 85, and when the user operates the release switch 85 in the circumferential direction, the release switching ring 82 rotates around the optical axis in conjunction with this.

The release member 81 is provided with linearly moving keys 81a oriented in the optical axis direction at three locations in the circumferential direction on the outer peripheral surface, and slides on vertical grooves 92a provided on the inner peripheral surface of the second fixed ring 92. In addition, the rotation around the optical axis is restricted inside the second fixed ring 92 so as to be able to go straight. Further, the release member 81 is provided with an engagement protrusion 81b that faces the release cam 82a of the release switching ring 82 in the optical axis direction. Further, the entire surface of the release member 81 on the subject side in the optical axis direction is opposed to a step surface (reference numeral omitted) provided on the drive ring 51 and directed toward the image plane side in the optical axis direction. Ribs 81c are formed.

  The presser ring 84 is fixed to the front side portion of the second fixed ring 92 with a screw or the like. A plurality of (six in the embodiment) compression coil springs 83 are interposed between the presser ring 84 and the release member 81 at a plurality of locations in the circumferential direction. It is biased toward the image plane side in the axial direction. By this urging, the engaging protrusion 81 b of the releasing member 81 comes into contact with the releasing cam 82 a of the releasing switching ring 82 and urges the releasing switching ring 82. The release switching ring 82 is held between the release member 81 and a plurality of pressing ribs 92 b provided on the inner peripheral surface of the second fixed ring 92.

  As described above, the release switch 85 can be operated by the user to slide the release switch 85 along the peripheral surface of the lens barrel 1 and is supported by the release switch mounting member 86 described above. A conductive brush 87 and a leaf spring 88 are attached to the release switch attachment member 86.

  The conductive brush 87 is in electrical contact with a flexible printed circuit board (not shown) disposed in the lens barrel, and detects the rotational position of the release switch 85. As shown in FIG. 6, the leaf spring 88 is for transmitting the switch when the user operates the operation switch 85, and a bent portion 88 a at the tip is formed on the inner peripheral surface of the second fixed ring 92. By entering the valley portions 92c and 92d, the switch is switched to the user as a click feeling.

  Next, the operation of the release mechanism 8 will be described. FIG. 8 is a diagram schematically showing a part of the release switch 85, the release switching ring 82, and the presser ring 84, and is a view of the release mechanism 8 virtually viewed from above the lens barrel. This will be described with reference to FIGS. 8, 4A and 4B. When the user operates the release switch 85 and is slid to the upper side of the lens barrel, that is, the bent portion 88a of the leaf spring 88 is at the valley portion 92c, and manual focus adjustment is possible. It becomes a state. At this time, this operation position can be detected by the conductive brush 87.

  That is, as shown in FIG. 8A, when the release switch 85 is operated to a position where manual focus adjustment is possible, the release switching ring 82 is rotated to a position where the release cam 82a and the engagement protrusion 81b do not contact each other. The Therefore, the release member 81 is moved to the image plane side by the urging force of the compression coil spring 83, and the rib 81 c of the release member 81 is separated from the step surface of the drive ring 71. Therefore, as shown in FIG. 4A, the sliding surface 71 a of the driving ring 71 is pressed against the planetary roller 55 by the urging force of the first wave washer 71. Therefore, when the user operates the focus operation ring 73, the output ring 51 rotates and the focus can be adjusted manually.

  On the other hand, in FIG. 6, when the release switch 85 is slid in the clockwise direction from the position shown in the drawing, that is, downward of the lens barrel, and the bent portion 88a of the leaf spring 88 reaches the valley portion 92d, manual focus adjustment is performed. It becomes a released state. As shown in FIG. 8B, when the release switch 85 is operated to a position where manual focus adjustment is released, the release switching ring 82 is rotated to a position where the release cam 82a and the engagement protrusion 81b abut. Therefore, as shown in FIG. 4B, the release member 81 is moved toward the subject against the biasing force of the compression coil spring 83, and the rib 81 c of the release member 81 contacts the step surface of the drive ring 71. As a result, the drive ring 71 is moved toward the subject against the urging force of the first wave washer 71, and the sliding surface 71 a of the drive ring 71 is separated from the planetary roller 55. Therefore, even if the user operates the focus operation ring 73, the output ring 51 does not rotate, and manual focus adjustment cannot be performed.

  When it is detected that the release switch 85 has been operated to the release position by the conductive brush 87, the focus motor 3 is turned off by the control circuit, which is not described, and the focus adjustment by the automatic focus adjustment is prohibited.

  As described above, in the first embodiment, the release switch 85 is operated in the circumferential direction of the lens barrel so that the operation by the focus operation ring 73 can be performed or the operation is canceled. Therefore, as compared with the case of operating in the optical axis direction of the lens barrel as in Patent Documents 1 and 2, the operability during imaging is improved and the holding of the imaging device during operation is stable.

  In particular, in the first embodiment, the relatively heavy focus motor 3 is disposed closer to the image plane side in the lens barrel 1, and the release switch 85 is positioned closer to the subject than the focus motor 3, and the focus Since the lens barrel 1 is disposed at a substantially intermediate position in the optical axis direction of the lens barrel 1 on the image plane side with respect to the operation ring 73, the moment generated in the lens barrel 1 when the release switch 85 is operated is reduced, and the lens mirror is reduced. This is advantageous in keeping the optical axis direction of the cylinder 1 stable.

  Further, in the first embodiment, when the manual focus adjustment is released, the release member 81 pushes the drive ring 71 to release the connection between the drive ring 71 and the planetary roller 55, so that the focus operation is performed. The release can be executed at an arbitrary position regardless of the rotation position of the ring 73, and the shift of the focus position due to the minute rotation of the focus operation ring 73 as occurred in Patent Document 1 can be prevented. Further, since the play caused by the component tolerance is not related, the shift of the focal position can be surely prevented.

  Furthermore, in the first embodiment, when the manual focus adjustment is canceled, the driving ring 71 is moved to the subject side and the first wave washer 72 is further pushed in. Thus, the elastic return force of the first wave washer 72 is increased. Increase. Accordingly, since the rotational torque when operating the focus operation ring 73 increases, it becomes easy for the user to understand that the operation force is released from the increase in the operation force of the focus operation ring 73.

  Even when manual focus adjustment is canceled, the planetary roller 55 of the output ring 51 is in pressure contact with the sliding surface 61a of the drive gear ring 61 for performing automatic focus adjustment. Thereby, even when vibration or the like is applied to the lens barrel 1 at the time of release, the output ring 51 does not rotate carelessly, and it is possible to reliably prevent the focal position from deviating.

(Embodiment 2)
FIG. 9A is a cross-sectional view of Embodiment 2 configured as a release switching ring member 82A in which the release switching ring 82 and the release member 81 in Embodiment 1 are integrated. Portions equivalent to those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In the second embodiment, as shown in a perspective view of the release switching ring member 82A in FIG. 10, a tapered release cam 82a is provided on the image side surface of the release switching member 82A. Further, an engagement projection 92b is provided on the surface of the second fixed ring 92 facing the release cam 82a in the optical axis direction and directed in the optical axis direction. The release cam 82a and the engagement protrusion 92b are engaged or not engaged according to a change in the rotational position of the release switching ring member 82A. The release switching ring member 82A is housed in the inner diameter position of the second fixed ring 92 so as to be slightly movable in the optical axis direction, and is moved to the image plane side by a compression coil spring 83 interposed between the press ring 84. Be energized. The compression coil spring 83 may be composed of a third wave washer. As a result, the release cam 82a is biased in a direction in which the release cam 82a abuts on the engagement protrusion 92b.

  In the second embodiment, when the release switch 85 is operated in the circumferential direction, as shown in FIG. 9A, the release switching ring member 82A rotates in the circumferential direction, and the release cam 82a comes into contact with the engagement protrusion 92b or comes into contact. It will be in a state that does not. When the release cam 82a does not come into contact with the engagement protrusion 92b, the release switching ring member 82A is at the position on the image plane side by the urging force of the compression coil spring 83. Further, the drive ring 71 is pressed toward the image plane side by the first wave washer 72. As a result, the sliding surface 71 a of the drive ring 71 is pressed against the planetary roller 55. Therefore, when the user operates the focus operation ring 73, the output ring 51 rotates and manual focus adjustment can be performed.

  On the other hand, when the release cam 82a comes into contact with the engagement protrusion 92b by operating the release switch 85, the release switching ring member 82A is moved toward the subject against the urging force of the compression coil spring 83, as shown in FIG. The drive ring 71 is moved to the subject side. As a result, the sliding surface 71a of the drive ring 71 is separated from the planetary roller 55 and is released. Therefore, even if the user operates the focus operation ring 73, the output ring 51 does not rotate, and manual focus adjustment cannot be performed.

  In the second embodiment, since the drive ring 71 can be moved in the optical axis direction by one release switching ring member 82A to connect and release the differential mechanism 6, the number of parts of the lens barrel 1 can be reduced. This is advantageous for reducing the size of the lens barrel 1.

(Embodiment 3)
FIG. 11A is a cross-sectional view of Embodiment 3 in which the release switching ring 82 and the release member 81 in Embodiment 1 are configured with a cam groove structure. Portions equivalent to those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In the third embodiment, the release switching ring 82 is formed in a cylindrical shape, and a cam groove 82c is provided on the peripheral surface thereof. The release member 81 is disposed on the inner diameter side of the release switching ring 82, and a roller 81d that engages with the cam groove 82c is provided on a part of the release member 81. Further, an auxiliary drive ring 71A is connected to the drive ring 71 in the optical axis direction by screws, and a part of the release member 81 is sandwiched between the drive ring 71 and the auxiliary drive ring 71A in the optical axis direction. The driving ring 71 has a sliding surface 71 a on the image plane side arranged to face the planetary roller 55, and the auxiliary driving ring 71 A is engaged with the focus operation ring 73. Here, the first wave washer 72 of the first embodiment is not provided.

  In the third embodiment, when the release switch ring 82 is rotated by operating the release switch 85, the release member 81 moves to the image plane side in the optical axis direction by sliding between the cam groove 82c and the roller 81d as shown in FIG. 11A. To do. As a result, the drive ring 71 and the auxiliary drive ring 71A holding the release member 81 also move to the image plane side. Accordingly, by appropriately designing the shape of the cam groove 82c, when the release switch 85 is operated to a position where manual focus adjustment is possible, the drive ring 71 moves to the image plane side, and the sliding surface 71a moves to the planetary roller 55. Thus, manual focus adjustment by the focus operation ring 73 becomes possible.

  On the other hand, when the release switch 85 is operated to the position for releasing the manual focus adjustment, the release member 81 is moved to the subject side by the sliding of the cam groove 82c and the roller 81d accompanying the rotation of the release switching ring 82 as shown in FIG. 11B. The drive ring 71 and the auxiliary drive ring 71A move toward the subject side. As a result, the sliding surface 71a of the drive ring 71 is separated from the planetary roller 55, and manual focus adjustment by the focus operation ring 73 cannot be performed. At this time, the drive gear ring 61 is moved to the subject side by the second wave washer 62. In the third embodiment, since the groove 53a and the ball 54 of the rear support ring 53 are not provided as in the first and second embodiments, the output ring 51 is also moved to the subject side with the movement of the drive gear ring 61. However, since the end surface 51 a on the subject side of the output ring 51 is in contact with the second support ring 57, the movement is restricted, and the state where the drive ring 71 is separated from the planetary roller 55 is maintained.

  In these Embodiments 2 and 3, the form of the release switch 85 provided in the lens barrel 1 is the same as that in Embodiment 1, and it is needless to say that the same effect as in Embodiment 1 can be expected.

  The present invention is not limited to the lens barrel such as the interchangeable lens described above, but can also be applied to a lens barrel integrated with the camera body. Further, the present invention is not limited to the lens barrel of a still image shooting camera, but can be applied to a lens barrel of a moving image shooting camera and a lens barrel of a digital imaging apparatus. Furthermore, it goes without saying that the present invention includes a configuration in which the lens barrel is configured as an interchangeable lens, or as a camera or an imaging device for moving image shooting that is integrated into the apparatus main body.

1 Lens barrel 2 Camera body 3 Focus motor (actuator)
4 Automatic focus adjustment mechanism 5 Manual focus adjustment mechanism 6 Differential mechanism (planetary mechanism)
8 Release mechanism 51 Output ring (planet carrier)
55 Planetary Roller (Planet)
61 Drive gear ring (second solar wheel)
71 Drive ring (first solar wheel)
73 Focus operation ring (manual focus adjustment ring)
81 Release member 82 Release switching ring 82A Release switching ring member 84 Presser ring 85 Release switch (release operation member)
L1-L5 group lens

Claims (9)

An optical system having a plurality of lenses, and a focus adjustment mechanism for adjusting a focus by moving a part of the lenses of the optical system in the optical axis direction, the focus adjustment mechanism having a differential mechanism having two input units The lens barrel is connected to one input section with manual focus adjustment means for performing focus adjustment by manual operation, and to the other input section with automatic focus adjustment means for performing focus adjustment with an actuator. In
A release mechanism for releasing the connection of the manual focus adjustment means to the differential mechanism, and a release operation member for operating the release mechanism moves in a circumferential direction of the lens barrel on the peripheral surface of the lens barrel; A lens barrel characterized by being arranged to be operable.   An operation ring for operating the manual focus adjusting means is disposed on the subject side of the lens barrel, the actuator is disposed on the image plane side of the lens barrel, and the release operation member is formed of the operation ring and the actuator. The lens barrel according to claim 1, which is disposed at an intermediate position in the optical axis direction.   The differential mechanism includes a planetary mechanism having first and second solar wheels, a planet, and a planet carrier, the first solar wheel is configured as the one input unit, and the second solar wheel is the other solar wheel. The lens barrel according to claim 1, wherein the lens barrel is configured as an input unit, and the planetary carrier is configured to move the partial lens in the optical axis direction. The differential mechanism is
An output member as the planet carrier that rotates around the optical axis;
A planetary roller as the planet supported by an axis extending in a direction orthogonal to the optical axis provided in the output member;
The manual focus adjusting means as the first sun wheel facing the planetary roller from one side in the optical axis direction;
The automatic focus adjustment means as the second sun wheel facing the planetary roller from the other in the optical axis direction;
First pressing means for pressing the manual focus adjusting means against the planetary roller;
Second pressing means for pressing the automatic focus adjusting means against the planetary roller;
The lens barrel according to claim 3, comprising:   The manual focus adjusting unit includes an operation ring and a drive ring for performing manual operation, and the drive ring is rotatable in an optical axis direction relative to the operation ring while being rotatable integrally with the operation ring. The lens barrel according to claim 4, wherein the lens barrel is movable, and the driving ring is brought into pressure contact with the planetary roller by the first pressing means and is released from a pressure contact state with the planetary roller when released.   The release mechanism includes a release switching member that rotates around the optical axis by operation of the release operation member, and a release member that moves in the optical axis direction, and the release switch member is engaged with the release member by a cam mechanism, 6. The lens mirror according to claim 5, wherein when the lens is rotated, the release member is moved in the optical axis direction to release the drive ring from a pressure contact state with the planetary roller against a pressure contact force of the first pressing means. Tube.   The cam mechanism includes a plurality of release cams provided in a circumferential direction on a surface of the release switching member that faces the release member, and is provided in a circumferential direction on a surface of the release member that faces the release switching member. The lens barrel according to claim 6, comprising a plurality of protrusions that contact the release cam.   The release mechanism includes a release member that is cam-engaged with a fixed ring of the lens barrel, and the release member rotates around the optical axis by the operation of the release operation member, and the optical axis by the cam engagement. The lens barrel according to claim 6, wherein the manual focus adjusting unit is released from the press contact state with the planetary roller against the press contact force of the first pressing unit when the manual focus adjustment unit moves in the direction. An imaging device comprising the lens barrel according to claim 1.

Images